In residential buildings, external side walls may be made from a variety of materials. Bricks or stone walls are common. However, in some historical districts of cities, standards may be set for compulsory wooden side walls. Wooden side-wall shingles are then recommended, to facilitate withstanding of weathering forces. A water barrier membrane is typically installed against the building side wall, and then the shingles are installed one by one by semi-skilled workers standing outside the building. This is labour intensive and does not enable perfect waterproofness of installation. The shingles may be offset or tilted relative to one another, providing an odd or unbalanced view. Some moisture can become undesirably trapped between the water barrier membrane and the shingles, thus compromising the useful lifetime of the shingles, especially if keyway slots extend between each pair of successive shingle from a given horizontal row of shingles.
As an alternate mode of installation, a number of similarly sized shingles may be factory installed to the water barrier membrane and associated plywood board, and then shipped as an integral module to the construction site. This multiple shingles module may be installed directly against the building side wall, adjacent another shingles module, and then interlocked to one another about an edgewise joint. However, such shingles modules are still damaged quite rapidly by weathering forces, and are thus short lasting in useful lifetime due to moisture borne loads. The reason for such inefficiency is that the layer of shingles is not per se waterproof, since a number of water seeping gaps exist along this first “line of defense” of the side wall. Hence, some water from rain, snow or the like is allowed to seep in between shingles, to become trapped between the water barrier membrane and the shingles. This trapped moisture is what is deleterious to the useful life time of the shingles.